Electronic device capable of appropriately using various time displays

ABSTRACT

An electronic device includes first and second processors, and first and second display units. While the first and second processors cooperate with each other and perform a display operation including a time display, the first processor can be set to a normal mode, a low power mode in which a power consumption is lower than a power consumption in the normal mode, or a pause mode in which a power consumption is lower than the power consumption in the low power mode, and the first processor is stopped. In the normal or low power modes, the first processor controls such that the first display unit displays a time, and the second processor controls such that the second display unit does not display a time. In the pause mode, the first display unit is turned off, and the second processor controls such that the second display unit displays a time.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. application Ser.No. 16/355,529, filed Mar. 15, 2019, which is a Divisional applicationof U.S. application Ser. No. 15/373,423, filed Dec. 8, 2016, which isbased on and claims priority from Japanese Patent Application No.2016-058331, filed Mar. 23, 2016. The entire contents of all of theabove-identified applications are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to an electronic device capable ofappropriately using various time displays.

BACKGROUND OF THE INVENTION

Conventionally, an electronic device (electronic display apparatus)includes a display unit and can display each kind of information. Theelectronic display device can cause the display unit to displayvariously in response to improvement on a display screen. In addition,conventionally, the electronic display device includes a plurality ofdisplay units and has a technique to appropriately use a plurality ofdisplay units according to a display content (for example, refer to JP2006-101505 A).

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is providedan electronic device, including: a first processor; a second processor;a first display unit; and a second display unit, wherein while the firstprocessor and the second processor cooperate with each other and performa display operation including a time display, time display processing isperformed to at least either of the first display unit or the seconddisplay unit according to an operation state.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an elevation view of a smart watch according to an embodimentof an electronic device in the present invention;

FIG. 1B is an elevation view of a smart watch according to theembodiment of the electronic device in the present invention;

FIG. 2 is a block diagram illustrating a functional configuration of thesmart watch;

FIG. 3A is an elevation view illustrating an example of a display statein the case where the smart watch is in each power consumption mode;

FIG. 3B is an elevation view illustrating an example of a display statein the case where the smart watch is in each power consumption mode;

FIG. 3C is an elevation view illustrating an example of a display statein the case where the smart watch is in each power consumption mode;

FIG. 3D is an elevation view illustrating an example of a display statein the case where the smart watch is in each power consumption mode;

FIG. 4 is a flowchart illustrating a control procedure in displaycontrol processing performed by a main CPU;

FIG. 5 is a flowchart illustrating a control procedure in displaycontrol processing performed by a sub CPU;

FIG. 6 is a flowchart illustrating a control procedure in displaycontrol processing according to a first variation by a main CPU;

FIG. 7 is a flowchart illustrating a control procedure in the displaycontrol processing according to the first variation by a sub CPU;

FIG. 8 is a flowchart illustrating a control procedure in displaycontrol processing according to a second variation by a main CPU;

FIG. 9 is a flowchart illustrating a control procedure in displaycontrol processing according to a third variation by a main CPU; and

FIG. 10 is a flowchart illustrating a control procedure in the displaycontrol processing according to the third variation by a sub CPU.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments in the case where an electronic device in thepresent invention is realized as a smart watch will be described withreference to drawings.

FIGS. 1A and 1B are elevation views of a smart watch 100 according tothe embodiment of the electronic device in the present invention.

As illustrated in FIG. 1A, the smart watch 100 is a wrist mounting typeelectronic device in which a watch body 1 is mounted around user's wristby using a band 2. The watch body 1 of the smart watch 100 includes aframe 3, a display screen 4, and a push button switch B1.

The push button switch B1 is provided on a side surface of the frame 3and receives a pushing operation by a user. When the push button switchB1 is pressed, a power mode is returned from a low power mode or a pausemode to a normal mode to be described later.

A display unit having two screens is stacked on the display screen 4. Asillustrated in FIG. 1B, a display screen 12 a of a first display unit 12(refer to FIG. 2 ) is provided in a lower portion, and a display screen22 a of a second display unit 22 (refer to FIG. 2 ) is provided in anupper portion. Specifically, FIG. 1A illustrates a state in which thefirst display unit 12 performs display, and the display screen 22 a ofthe second display unit 22 transmits the display by the first displayunit 12.

In a further upper portion of the second display unit 22, a touch sensor(not illustrated) is provided and receives a user operation togetherwith the push button switch B1.

The first display unit 12 includes a dot matrix type color liquidcrystal display screen and switches and/or parallelly performs variousdisplays regarding each function according to an input operation by auser and each program operation.

The second display unit 22 includes a display screen capable ofdisplaying a time by a simple display with low power consumption incomparison with the first display unit 12 and, for example, performssegment type monochrome liquid crystal display. Alternatively,Memory-In-Pixel (MIP) liquid crystal, Polymer Network (PN) liquidcrystal, or the like may be used for the display screen 22 a of thesecond display unit 22. Further, the display screen 22 a of the seconddisplay unit 22 can transmit a display content of the first display unit12 upward. In this case, the second display unit does not display at allsince a predetermined voltage is applied.

FIG. 2 is a block diagram illustrating a functional configuration of thesmart watch 100 according to the embodiment.

The smart watch 100 includes a main microcomputer 11, the first displayunit 12 (first display unit), an operation receiving unit 13, a wirelesscommunication controller 14, a satellite radio wave receiving module 15,a sub microcomputer 21, a second display unit 22 (second display unit),a switch 23, a PMIC 31 (Power Management IC), and the like.

The main microcomputer 11 is a main control unit including a main CPU111 (first processor), a RAM 112, a storage unit 113, and the like. Themain microcomputer 11 controls each operation of the first display unit12, the operation receiving unit 13, the wireless communicationcontroller 14, the satellite radio wave receiving module 15, and thelike by receiving power supply from a power source by control of thePMIC 31.

The main CPU 111 performs each arithmetic processing and totallycontrols operations in a normal operation state of the smart watch 100.

The RAM 112 provides a working memory space to the main CPU 111 andtemporarily stores data. The RAM 112 stores and holds information on atime counted by the main CPU 111 as a first clock unit based on a clocksignal (not illustrated). Hereinafter, “time” may mean “date and time”including a date.

The storage unit 113 is a nonvolatile memory such as a flash memory forstoring a control program and a set data performed by the main CPU 111.

A display operation of the above-described first display unit 12 iscontrolled by mainly the main microcomputer 11 (main CPU 111 (refer toFIG. 2 )). However, the sub microcomputer 21 (sub CPU 211 (refer to FIG.2 )) can perform display control.

The operation receiving unit 13 includes the above-described push buttonswitch B1 and a touch sensor. The operation receiving unit 13 receivesan input operation by a user, converts an operation content into anelectrical signal, and outputs the signal to the main CPU 111.

The wireless communication controller 14 is a controller for performingwireless communication with an external electronic device. Examples of awireless communication standard include, but not especially limited to,short-range wireless communication such as Bluetooth (a registeredtrademark) and a wireless LAN (IEEE802.11). The main microcomputer 11(main CPU 111) can obtain necessary information and programs, updatedata thereof, and the like can be obtained from outside via the wirelesscommunication controller 14. Examples of the external electronic deviceto be communicated include a smart phone, a cell phone, a tabletterminal, and a personal digital assistant (PDA). Among them,especially, when a smart phone and a cell phone are connected to a basestation, time information is synchronized, and time accuracy ismaintained. In the case where the main CPU 111 communicates and connectsto a smart phone and a cell phone, the main CPU 111 acquires timeinformation from these external devices and can correct a counting timebased on the acquired time information.

The satellite radio wave receiving module 15 can capture, receive, anddemodulate radio waves from a positioning satellite, at least asatellite related to a global positioning system (GPS) (GPS satellite)and can perform time acquisition and positioning. The satellite radiowave receiving module 15 includes an antenna (not illustrated) andperforms inverse spectral diffusion by receiving radio waves from the L1band (1.57542 GHz in a GPS satellite) based on control of the mainmicrocomputer 11 (main CPU 111). Then, the satellite radio wavereceiving module 15 obtains and decrypts a navigation message andoutputs the message by a predetermined format.

The sub microcomputer 21 includes a sub CPU 211 (second processor) andan RTC 212 (real time clock and a second clock unit). The submicrocomputer 21 operates by receiving power supply from a power sourceby control of the PMIC 31 and mainly controls an operation of the seconddisplay unit 22.

The sub CPU 211 performs each arithmetic processing and controlsoperations of the sub microcomputer 21. The sub CPU 211 operates with alow power consumption and a low operation frequency in comparison withthe main CPU 111. Accordingly, the sub CPU 211 may have a lower capacitythan the main CPU 111. The sub CPU 211 operates, for example, at aregular timing to perform a predetermined operation and when detectingan input from the main CPU 111 and the switch 23, and the sub CPU 211may be in a standby state other than during the above.

The RTC 212 is usually used to count a time and preferably operates witha low power consumption.

As described above, the second display unit 22 operates with a low powerconsumption in comparison with the first display unit 12 and also isused for a time display during a display operation. In the case whereMIP liquid crystal is used for a display screen, the sub CPU 211 canreduce a frequency to update a display content. Therefore, during anupdate interval, the sub CPU 211 can be in the standby state.

The switch 23 is an on-switch which receives a predetermined useroperation to restart the main microcomputer 11 in the case where themain microcomputer 11 is in a pause state. The switch 23 may beexclusively provided and may be used with the push button switch B1.

The PMIC 31 controls power supply to the main microcomputer 11 and thesub microcomputer 21 from a power source. The PMIC 31 includes, forexample, a switch for switching power output availability to the mainmicrocomputer 11 and the sub microcomputer 21 and a DC/DC converter foradjusting an output voltage, or the like, and power is appropriatelysupplied while the main microcomputer 11 and the sub microcomputer 21are operated.

Further, the PMIC 31 includes a counter 311 (first counting unit) and anRTC 312 (third clock unit).

The counter 311 counts a predetermined clock signal and outputs thesignal periodically (at predetermined time intervals) for every setcount values. As the clock signal, an oscillation signal of anoscillator included in the RTC 312 or a signal obtained byfrequency-dividing the oscillation signal is used.

The RTC 312 is generally used to count a time. This RTC 312 may be thesame type with the RTC 212 or may be a different type.

Next, a display operation and a power control by the smart watch 100according to the embodiment will be described.

Three power consumption modes (operation states) can be set in the smartwatch 100. As this power consumption mode, with respect to a normal modefor normal operation, a low power mode and a pause mode are set. In thelow power mode, a power consumption is lower than a power consumption inthe normal mode. In the pause mode, a power consumption is lower than apower consumption in the low power mode.

FIGS. 3A to 3D are elevation views exemplifying a display state in thecase where the smart watch 100 is in each power consumption mode.

The normal mode is a mode capable of executing every normal interactivefunctions included in the smart watch 100. In the normal mode, the mainmicrocomputer 11 is mainly operated, and as illustrated in FIG. 3A, eachtype of display operation is performed to the first display unit 12 bycontrol of the main CPU 111. A time display can be included in a contentto be displayed by the first display unit 12. In this case, a hour hand,a minute hand, and a second hand are displayed in the time display, andthe time display is updated per second (a first time interval) by movingthe second hand. Further, in the case where specific functionaloperation is performed, a time cannot be temporarily displayed in thesmart watch 100.

The low power mode is a temporary power consumption mode in the casewhere a standby state is continued during an operation in the normalmode, for example. The mode is immediately returned to the normal modein the case where an input operation to the operation receiving unit 13by a user is detected and in the case where a display content related toa function performed in the normal mode is updated, for example. In thelow power mode, as illustrated in FIG. 3B, a time display is performedto the first display unit 12 by control of the CPU 111. However, a powerconsumption related to the display is reduced by limiting a displaycolor, a luminance, and an update interval in comparison with a displaystate in the normal mode. For example, here, by erasing a drawing of asecond hand, drawing of a hour hand and a minute hand is updated at apredetermined time interval, for example, every ten seconds or oneminute.

FIGS. 3A and 3B exemplify time displays, and an analog clock display inwhich a pointer is drawn on a display screen is indicated. However, anormal digital clock display in which a time is indicated by numericalvalues may be used.

In the pause mode, an operation of the main microcomputer 11 is stopped,and the sub microcomputer 21 is operated. An operation of the firstdisplay unit 12 is also stopped when an operation of the mainmicrocomputer 11 is stopped, and the second display unit 22 display atime by control of the sub CPU 211 of the sub microcomputer 21 asillustrated in FIG. 3C. Here, a time display is updated per second.However, a power consumption related to a display by an operation of thesecond display unit 22 and the sub CPU 211 with a low power consumptionis lower than a power consumption related to a display by operations ofthe first display unit 12 and the main CPU 111 in the low power mode.The mode transits to the pause mode in the case where an explicitinstruction is received by a predetermined operation by a user and inthe case where it becomes difficult to maintain a stable operation ofthe main microcomputer 11 since power supply from a power source isinsufficient. In the smart watch 100, the mode is returned from thepause mode to the normal mode when the switch 23 is pressed in the pausemode.

FIG. 4 is a flowchart illustrating a control procedure in displaycontrol processing performed by the main CPU 111 in the smart watch 100according to the embodiment.

This display control processing is started when the main CPU 111 isstarted and continuously performed until being turned off.

The main CPU 111 first performs processing to start the mainmicrocomputer 11 (step S101). The main CPU 111 requests time informationby sending a control signal to the sub CPU 211 and starts counting atime based on time data of the RTC 212 received from the sub CPU 211(step S102). The main CPU 111 starts a display of the first display unit12 in the normal mode and stops a display of the second display unit 22by outputting a control signal to the sub CPU 211, and the seconddisplay unit 22 transmits the display by the first display unit 12 (stepS103).

The main CPU 111 determines whether an input operation to the operationreceiving unit 13 is detected or whether an input related to a displayupdate operation regarding a function being operated is performed (stepS104). In the case where neither is determined (“NO” in step S104), themain CPU 111 determines whether an input operation detection and adisplay update operation are not input for a predetermined time orlonger (step S105). In the case where it is determined that both of themare input within the predetermined time (“NO” in step S105), processingof the main CPU 111 is returned to step S104. In the case where it isdetermined that neither is input for the predetermined time or longer(“YES” in step S105), the processing of the main CPU 111 is moved tostep S106.

In the case where it has been determined in the determination processingin step S104 that the input operation is detected or a display updateoperation is input (“YES” in step S104), the main CPU 111 determineswhether an input detection content is an instruction for transition to alow power mode (step S115). In the case where it is determined that thecontent is the instruction for transition to the low power mode (“YES”in step S115), processing of the main CPU 111 is shifted to step S106.

In the case where it is determined that the content is not theinstruction for transition to the low power mode (“NO” in step S115),the main CPU 111 determines whether an input detection content is aninstruction for transition to a pause mode (step S125). In the casewhere it is determined that the content is not the instruction fortransition to the pause mode (“NO” in step S125), the main CPU 111performs operation and display according to the other detected contents(step S126). Then, processing of the main CPU 111 is shifted to stepS104.

When the processing is shifted from steps S105 and S115 to step S106,the main CPU 111 changes a power consumption mode to a low power mode,and a display of the first display unit 12 is changed to a display statein the low power mode (step S106). The main CPU 111 updates a timedisplay per minute by the first display unit 12 (step S107) and alsodetermines whether an input operation is detected or a display updateoperation is input (step S108). In the case where it is determined thatneither is determined (“NO” in step S108), processing of the main CPU111 is returned to step S107. In the case where either of them isdetermined (“YES” in step S108), the main CPU 111 changes a powerconsumption mode to a normal mode and changes the display of the firstdisplay unit 12 to a normal mode display state (step S109). Then,processing of the main CPU 111 is returned to step S104.

In the case where it is determined in the determination processing instep S125 that an instruction for transition to the pause mode isdetected (“YES” in step S125), the main CPU 111 stops a displayoperation of the first display unit 12 and also causes the sub CPU 211to start and control a display operation of the second display unit 22by outputting a control signal to the sub CPU 211 (step S131).

The main CPU 111 outputs a control signal to the sub CPU 211 and thePMIC 31 and causes them to correct times to be counted by the RTCs 212and 312 according to the counted time (step S132). The main CPU 111performs processing to stop an operation of the main microcomputer 11and stops an operation of the main microcomputer 11 including the mainCPU 111 (step S133) and finishes display control processing.

FIG. 5 is a flowchart illustrating a control procedure of displaycontrol processing by the sub CPU 211.

This display control processing is started when the sub CPU 211 isstarted and continuously performed. After starting, the submicrocomputer 21 in the smart watch 100 according to the embodiment isnot turned off until a power source is removed, or a battery runs out.

The sub CPU 211 performs processing to start the sub microcomputer 21(step S201). Then, the sub CPU 211 waits until an input regarding acontrol operation is detected (step S202). In this case, this waitingprocessing is to wait for an interruption signal, and it is notnecessary to positively perform the waiting processing.

When the interruption signal is input, the sub CPU 211 determines aninput content. The sub CPU 211 determines whether the interruptionsignal is a time input from the RTC 212 and also whether the seconddisplay unit 22 is in a display operation state (step S203). In the casewhere the sub CPU 211 determines that the interruption signal is a timeinput, and the second display unit 22 is in the display operation state(“YES” in step S203), the sub CPU 211 outputs a control signal to updatea time display of the second display unit 22 to the second display unit22 (step S204). Then, processing of the sub CPU 211 is returned to stepS202.

In the case where it is determined that the input content is not a time,or the second display unit 22 is not in a display operation state (“NO”in step S203), the sub CPU 211 determines whether a request of timeinformation from the main CPU 111 is input (Step S205). In the casewhere it is determined that the request of time information is input(“YES” in step S205), the sub CPU 211 obtains a time from the RTC 212and outputs the time to the main CPU 111 (step S206). Then, processingof the sub CPU 211 is returned to step S202.

In the case where it is determined that the request of time informationis not input from the main CPU 111 (“NO” in step S205), the sub CPU 211determines whether a request to start a display operation of the seconddisplay unit 22 is input from the main CPU 111 (step S207). In the casewhere it is determined that the request to start the display operationof the second display unit 22 is input (“YES” in step S207), the sub CPU211 starts a display operation of the second display unit 22 (stepS208). Then, processing of the sub CPU 211 is returned to step S202.

In the case where it is determined that the request to start a displayoperation of the second display unit 22 is not input from the main CPU111 (“NO” in step S207), the sub CPU 211 determines whether a request tofinish the display operation of the second display unit 22 is input fromthe main CPU 111 (step S209). In the case where it is determined thatthe request to finish the display operation of the second display unit22 is input (“YES” in step S209), the sub CPU 211 finishes the displayoperation of the second display unit 22 and the second display unit 22is put in a transmitting state (step S210). Then, processing of the subCPU 211 is returned to step S202.

In the case where it is determined that the request to finish thedisplay operation of the second display unit 22 is not input from themain CPU 111 (“NO” in step S209), the sub CPU 211 determines whether apushing operation of the switch 23 is detected (step S211). In the casewhere it is determined that the pushing operation of the switch 23 isdetected (“YES” in step S211), the sub CPU 211 operates to start themain CPU 111 (step S212). Then, processing of the sub CPU 211 isreturned to step S202.

In the case where it is determined that the pushing operation of theswitch 23 is not detected (“NO” in step S211), the sub CPU 211 performsprocessing in response to the other detected input (step S213). Then,processing of the sub CPU 211 is returned to step S202.

As described above, the smart watch 100 according to the embodimentincludes the main CPU 111, the sub CPU 211, the first display unit 12,and the second display unit 22. While the main CPU 111 and the sub CPU211 cooperate with each other, and perform a display operation includinga time display, time display processing is performed to at least eitherof the first display unit 12 or the second display unit 22 according toan operation state.

Thus, two CPUs cooperate with each other and control two display units.The CPUs can further flexibly and appropriately control various displaypatterns by causing either of the display units to display a timeaccording to an operation state.

In addition, the main CPU 111 can be selectively set to any of aplurality of power consumption modes as an operation state and thereforecan improve an operation efficiency by appropriately using a displayunit and a CPU according to a power consumption.

Further, a plurality of the power consumption modes includes a normalmode, a low power mode, and a pause mode. A power consumption in the lowpower mode is lower than a power consumption in the normal mode. A powerconsumption in the pause mode is lower than a power consumption in thelow power mode, and the main CPU 111 is stopped in the pause mode. Thus,an operation according to a power consumption can be easily andappropriately selected by setting each operation state for each powerconsumption and appropriately combining a display unit for performing adisplay operation and a CPU for performing a control operation in eachstate.

In addition, in the normal mode or the low power mode, the main CPU 111controls such that the first display unit 12 displays a time, and thesub CPU 211 controls such that the second display unit 22 does notdisplay a time. In the pause mode, the first display unit 12 is turnedoff, and the sub CPU 211 controls such that the second display unit 22displays a time.

Thus, the first display unit 12 is turned off when the main CPU 111 isturned off, a display is performed in combination with the sub CPU 211and the second display unit 22 which can be operated with a low powerconsumption, and consequently a time display with a minimum powerconsumption is performed easily and without difficulty.

Further, the main CPU 111 counts a time by using the RAM 112 by controlof the main CPU 111 as a first clock unit. The sub microcomputer 21includes the RTC 212 for counting a time separately from counting a timeby control of the main CPU 111 in the main microcomputer 11. The mainCPU 111 causes the first display unit 12 to display a time counted bythe main CPU 111. The sub CPU 211 causes the second display unit 22 todisplay a time counted by the RTC 212.

Thus, according to a power consumption mode, a time counting operationand a time display operation in the main microcomputer 11 and a timecounting operation and a time display operation in the sub microcomputer21 are separated. Therefore, in the smart watch 100, time counting and atime display according to consumption power are further easily andappropriately performed by switching operations of two microcomputers.

Further, when a power consumption mode is transited from the normal modeto the low power mode or the pause mode, the main CPU 111 corrects atime of the RTC 212 based on a time counted by the first clock unit.Therefore, even if a time counting operation by the main CPU 111 isstopped, a time difference of the RTC 212 is reduced, and an timedisplay can be easily performed for a while with accuracy as in countingby the main CPU 111.

Further, similarly, when the mode is transited from the normal mode tothe low power mode or the pause mode, the main CPU 111 corrects a timeof the RTC 312 based on a time counted by the first clock unit.Accordingly, as with the RTC 212, a time counting difference of the RTC312 is reduced, and a time display with accuracy as in a time counted bythe main CPU 111 can be easily performed for a while.

Further, the display screen 22 a of the second display unit 22 isstacked on an upper portion of the display screen 12 a of the firstdisplay unit 12, and the display screen 22 a is controlled such that adisplay content by the first display unit 12 is transmitted in a statein which a time is not displayed. Therefore, any display is performed ona display screen 4, which is a single screen on appearance, byappropriately using a display unit according to a power consumptionmode, and consequently a user can appropriately use various displayswithout the sense of incongruity.

In addition, the first display unit 12 includes a liquid crystal displayscreen capable of color display. That is, the first display unit 12 canperform various displays by using the color display at least in thenormal mode. On the other hand, in the case of an operation with a lowpower consumption, a power consumption amount can be efficiently reducedby performing driving control to cause the second display unit 22 toperform a display without using the color liquid crystal display screen.

In addition, control of the use of various displays can be easily andappropriately performed by performing the display control of a pluralityof display units by a plurality of CPUs in the above-described displaycontrol method.

First Variation

Next, a first variation of display control processing will be described.

In the display control processing in the first variation, a main CPU111, a wireless communication controller 14 (communication unit) and asatellite radio wave receiving module 15 (receiving unit) are includedin a time acquisition unit, a counted time is corrected by acquiring,from outside, more highly accurate time information than a time countedby the main CPU 111 and times counted by RTCs 212 and 312.

FIG. 6 is a flowchart illustrating a control procedure in displaycontrol processing in the first variation by the main CPU 111.

This display control processing is same as the display controlprocessing according to the above-described embodiment, other than thatprocessing in steps S151 to S153 is added, and also processing in stepsS107 a to S107 c is performed instead of processing in step S107, andthe processing as in the embodiment will be denoted by the samereference sign, and descriptions thereof are omitted.

After processing in step S103 is performed, the main CPU 111communicates with an external apparatus, such as a smart phone, via thewireless communication controller 14, obtains time information from theexternal apparatus, and corrects a counting time (step S151). The mainCPU 111 determines whether the time information acquisition fails (stepS152), and if it is determined that the acquisition fails (“YES” in stepS152), the main CPU 111 further acquires time information from apositioning satellite such as a GPS satellite by operating the satelliteradio wave receiving module 15 and corrects a counting time (step S153).Then, processing of the main CPU 111 is shifted to step S104. The mainCPU 111 may also correct a time of the RTC 312 based on the acquiredtime information. Further, the main CPU 111 may send the acquired timeto a sub CPU 211 and cause the sub CPU 211 to correct times counted bythe RTCs 212 and 312.

In the case where it is determined that the acquisition does not fail(“NO” in step S152), processing in the main CPU 111 is shifted to stepS104.

Further, when an operation mode transits to a low power mode inprocessing in step S106, the main CPU 111 causes a storage unit 113 as astoring unit to store counting times (step S107 a). As a result, themain CPU 111 stops a time counting operation. The main CPU 111 entersinto a waiting state for waiting for an input (calling). When the mainCPU 111 is called at predetermined intervals by a counter 311 of a PMIC31, for example called per minute, the predetermined interval, in otherwords, one minute, is added to the time stored in the storage unit 113,and the time stored in the storage unit 113 is updated to the added time(step S107 b). The main CPU 111 updates a time displayed by the firstdisplay unit 12 corresponding to a time stored in the storage unit 113(step S107 c), and then processing is shifted to step S108.

FIG. 7 is a flowchart illustrating a control procedure in the displaycontrol processing according to the first variation by the sub CPU 211.

With respect to the display control processing according to theabove-described embodiment, this display control processing is differentin the point in which processing in steps S251 and S252 is added. Theprocessing as in the embodiment is denoted by the same reference sign,and a description thereof is omitted.

When “NO” is selected in a determination processing in step S211, thesub CPU 211 determines whether conditions to change a power consumptionmode according to an operation state of the sub CPU 211 are satisfied(Step S251). In the case where it is determined that the conditions arenot satisfied (“NO” in step S251), processing by the sub CPU 211 isshifted to step S213. In the case where it is determined that theconditions are satisfied (“YES” in step S251), the sub CPU 211 changes asetting of a time interval to input time information to the sub CPU 211from the RTC 212 (step S252). Then, processing of the sub CPU 211 isreturned to step S202.

In the first variation, the sub CPU 211 can be set to two modesincluding a normal operation mode (second normal mode) and a low powerconsumption mode (second low power mode). In the normal operation mode,a time to be displayed by a second display unit 22 is updated persecond. In the low power consumption mode, the time to be displayed bythe second display unit 22 is updated per minute. That is, a time inputfrom the RTC 212 to the sub CPU 211 in step S203 is set per second inthe normal operation mode and set per minute in the low powerconsumption mode (in other words, a time interval in the low powerconsumption mode is longer than a time interval in the normal operationmode). Further, in response to this, as illustrated in FIG. 3D, in thecase of the low power consumption mode, a time to be displayed by thesecond display unit 22 is indicated in a minute digit, and a seconddigit is erased.

The operation mode of the sub CPU 211 is set separately from theabove-described power consumption mode. For example, the sub CPU 211 canbe changed to the low power consumption mode in the normal mode.

As described above, a smart watch 100 which performs display controlprocessing in the first variation includes the counter 311 for countinga predetermined interval, here, a minute interval. In the normal mode,the main CPU 111 causes the first display unit 12 to display a timecounted by the main CPU 111 at a first time interval which is shorterthan the predetermined time interval while updating per second. In thelow power mode, the main CPU 111 is called at predetermined tineintervals by the counter 311 and causes the first display unit 12 todisplay a time.

Therefore, in the low power mode, the main CPU 111 can be intermittentlyoperated, and a power consumption amount can be effectively reduced bylengthening the interval.

In addition, the main microcomputer 11 includes the storage unit 113,and when the operation mode is changed from the normal mode to the lowpower mode, the main CPU 111 causes the storage unit 113 to store a timecounted by the main CPU 111 and stops counting a time by the main CPU111. In the low power mode, when the main CPU 111 is called by thecounter 311, the main CPU 111 reads a time stored in the storage unit113, calculates a time obtained by adding a predetermined time intervalto the read time, and causes the first display unit 12 to display thecalculated time.

In this manner, a display on the first display unit 12 is updated bystopping time counting by the main CPU 111 and acquiring necessary timeinformation by appropriately and intermittently being called by acounting operation of the counter 311 separately operated from the mainCPU 111. Consequently, an arithmetic processing amount of the main CPU111 can be significantly reduced.

In addition, the sub CPU 211 can be selectively set to any of aplurality of power consumption modes as an operation state, and a normaloperation mode and a low power consumption mode are included. The normaloperation mode is a mode for normally operating the sub CPU 211. The lowpower consumption mode is a mode for operating the sub CPU 211 with alow consumption power in comparison with the normal operation mode. Inthis manner, a power consumption of the sub CPU 211 can be controlledaccording to an operation state, and a display can be furtherefficiently and appropriately controlled.

In addition, a sub microcomputer 21 includes the RTC 212. The RTC 212includes a counter (second counting unit) for counting a second timeinterval (one second or one minute). The sub CPU 211 is called at thesecond time interval by the counter of the RTC 212 and acquires a timecounted by the RTC 212. In the low power mode of the sub CPU 211, thesecond time interval is set to be longer than the interval in the normaloperation mode.

In this manner, by lengthening an interval to acquire time informationand an interval to update a display, necessary time information can beindicated flexibly at a necessary frequency while adjusting to anappropriate power consumption amount according to an operation state.

In addition, a time acquisition unit is included which acquires, fromoutside, more accurate time information in comparison with the countingoperation by the main CPU 111. The main CPU 111 corrects a time countedby the main CPU 111 based on the time acquired by the time acquisitionunit. Consequently, a difference in the time counted by the main CPU 111is appropriately corrected, and accurate time counting and display canbe continued.

In addition, in the case where the operation mode transits from the lowpower mode or the pause mode to the normal mode, the main CPU 111 causesthe time acquisition unit to acquire a time, and the main CPU 111corrects a counting time based on the acquired time. Therefore, in thesmart watch 100, accurate time counting/display can be performed fromthe beginning of an operation started in the normal mode.

In addition, the wireless communication controller 14 is included whichcommunicates to outside. The main CPU 111 acquires time information bythe wireless communication controller 14 from the outside, especially bya portable device such as a smart phone and a cell phone. Therefore, thesmart watch 100 can acquire easily and immediately accurate timeinformation from a familiar external device and can count and display anaccurate time.

In addition, a satellite radio wave receiving module 15 is includedwhich receives a satellite radio wave including time information from apositioning satellite and acquires time information. The main CPU 111acquires the time information acquired by the satellite radio wavereceiving module 15. Therefore, the smart watch 100 can acquire accuratetime information without sending a radio wave or communicating with anexternal apparatus. In addition, especially, a radio wave from apositioning satellite can be received outdoors all over the world, andwithout considering an area in which a communication wave can bereceived and transmitted, accurate time information can be obtained in awide area.

In addition, the sub CPU 211 can correct a time counted by the RTC 212based on a time acquired by the time acquisition unit. Consequently, inaddition to the case where the main CPU 111 counts a time, a differencein a time counted by the RTC 212 from an accurate time is minimized, andan accuracy of time counting/display in the pause mode may be improved.

Similarly, the sub CPU 211 can correct a time counted by the RTC 312based on a time acquired by the time acquisition unit. Consequently, adifference in a time counted by the RTC 312 from an accurate time can beminimized.

In addition, the first time interval for updating a time display in thenormal mode by the main CPU 111 is one second, and a predetermined timeinterval for updating a time display in the low power mode is oneminute. As described above, in the case where a user does not activelyuse the smart watch 100, even if a display update interval islengthened, the user does not have a significant issue, and a differencein a display state can be indicated to the user. Further, a powerconsumption can be effectively reduced.

Second Variation

Next, a second variation of display control processing will bedescribed.

FIG. 8 is a flowchart illustrating a control procedure in the displaycontrol processing in the second variation by the main CPU 111.

In the display control processing in the second variation, processing instep S107 d is performed instead of processing in steps S107 a and S107b in the display control processing in the first variation. Otherprocessing contents in the second variation are same as the processingcontents in the first variation. The same processing is denoted by asame reference sign, and a description thereof is omitted.

When an operation mode is changed to the low power mode in processing instep S106, a main CPU 111 stops counting a current time and enters intoa waiting state to wait for an input (calling). When the main CPU 111 iscalled by a counter 311 of a PMIC 31 at each predetermined timeinterval, the main CPU 111 acquires a current time from a RTC 312 of thePMIC 31 (step S107 d). Then, processing of the main CPU 111 is shiftedto step S107 c.

A calling operation may be performed by direct sending time informationfrom the RTC 312 of the PMIC 31 to the main CPU 111 at eachpredetermined time interval.

As described above, the smart watch 100 which performs display controlprocessing in the second variation includes the RTC 312 in the PMIC 31,and the RTC 312 counts a time separately from an RTC 212 and a timecounted by the main CPU 111. In the low power mode, the main CPU 111stops time counting by the main CPU 111, and when being called by thecounter 311, acquires a time from the RTC 312 and causes a first displayunit 12 to display the time. As a result, a power consumption can bereduced by significantly reducing a processing operation of the main CPU111. In addition, since a time display on the first display unit 12 isupdated by intermittently acquiring time information at a necessarytiming from the RTC 312 operating separately from an operation of a mainmicrocomputer 11 and a sub microcomputer 21, the main microcomputer 11and the sub microcomputer 21 are not operated more than necessary.

In addition, the RTC 312 is a real time clock. Therefore, a smart watch100 can efficiently count a time with a low power consumption regardlessof an operation of the main microcomputer 11 and the sub microcomputer21 by using a known IC chip, or the like.

Third Variation

Next, a third variation of display control processing will be described.

In display control processing in the third variation, in a low powermode, a sub CPU 211, not the main CPU 111, controls a display by a firstdisplay unit 12. A display content to the first display unit 12 in thelow power mode is not changed from the above-described embodiment andthe first and second variations. However, a display time is updatedbased on a time counted by an RTC 212.

FIG. 9 is a flowchart illustrating a control procedure in the displaycontrol processing in the third variation by the main CPU 111.

In the display control processing in the third variation, processing insteps S107 a to S107 c in the display control processing in the firstvariation is omitted, and also, instead of processing in steps S106 andS109, each of steps S106 e and S109 e is performed. Other processingcontents are same as the display control processing in the second andthird variations. The same processing is denoted by a same referencesign, and a description thereof is omitted.

When “YES” is selected in determination processing in step S105, themain CPU 111 performs each operation to transit to a low power mode. Atthis time, the main CPU 111 stops display control of the first displayunit 12, also stops time counting, and notifies the sub CPU 211 that anoperation mode is transited to the low power mode (step S106 e). Then,processing in the main CPU 111 is shifted to step S108, and the main CPU111 repeats the processing in step S108 or simply waits until anoperation input is detected or an input to update a display contentrelated to an operation of a predetermined functional operation unitcontrolled by the main CPU 111 is detected.

When “YES” is selected in processing in step S108, the main CPU 111performs each operation to transit to a normal power mode. In addition,at this time, the main CPU 111 sends, to the sub CPU 211, a notice thatan operation mode is returned to the normal mode and restarts timecounting by acquiring a time of the RTC 212. The main CPU 111 restartsdisplay control operation of the first display unit 12 (step S109 e).Then, processing of the main CPU 111 is returned to step S104.

FIG. 10 is a flowchart illustrating a control procedure in the displaycontrol processing according to the third variation by the sub CPU 211.

In the display control processing, processing in steps S261 to S264 isadded instead of steps S251 and S252 in comparison with the displaycontrol processing in the first variation. Further, other than thatprocessing in step S203 f is performed instead of processing in stepS203, and the display control processing is same as the display controlprocessing in the first variation. The same processing contents aredenoted by same reference signs, and descriptions thereof are omitted.

When an input is detected in processing in step S202, and the processingis shifted to step S203 f, the sub CPU 211 determines whether an inputcontent is time information, and the sub CPU 211 can control either ofthe first display unit 12 or the second display unit 22 (step S203 f).When it is determined that the time information is input, and the firstdisplay unit 12 is controlled (specifically, in a low power mode) or thesecond display unit 22 is controlled (specifically, in a pause mode)(“YES” in step S203 f), the sub CPU 211 updates a time display in thedisplay unit under control (step S204). Then, processing of the sub CPU211 is returned to step S202. When it is determined that timeinformation is not acquired, or the sub CPU 211 is not controlling thefirst display unit 12 and the second display unit 22 (“NO” in step S203f), processing by the sub CPU 211 is shifted to step S205.

In addition, in the case where “NO” is selected in the determinationprocessing in step S211, the sub CPU 211 determines whether a notice oftransition to a low power mode is obtained from the main CPU 111 (stepS261). In the case where it is determined that the notice to transitionto the low power mode is acquired (“YES” in step S261), the sub CPU 211starts display control of the first display unit 12 (step S262). Then,processing of the sub CPU 211 is returned to step S202.

In the case where it is determined that a notice to transition to alower power mode is not acquired (“NO” in step S261), and the sub CPU211 determines whether a notice to transition to a normal mode isacquired from the main CPU 111 (step S263). In the case where it isdetermined that the notice to transition to the normal mode is acquired(“YES” in step S263), the sub CPU 211 finishes display control of thefirst display unit 12 (step S264). Then, processing of the sub CPU 211is returned to step S202.

In the case where it is determined that the notice to transition to thenormal mode is not acquired (“NO” in step S263), processing by the subCPU 211 is shifted to step S213.

As described above, in the display control processing in the thirdvariation, in the normal mode, the main CPU 111 controls such that thefirst display unit 12 displays a time, and the sub CPU 211 controls suchthat the second display unit 22 does not display a time. In the lowpower mode, the sub CPU 211 controls such that the first display unit 12displays a time, and the second display unit 22 does not display a time.In the pause mode, the first display unit 12 is turned off, and the subCPU 211 controls such that the second display unit 22 displays a time.

In this manner, with respect to the normal mode in which the main CPU111 and the first display unit 12 are used, the sub CPU 211 is used toreduce a power consumption in the low power mode, and the powerconsumption is further reduced by using the second display unit 22 inthe pause mode. The smart watch 100 can be obtained in which variousdisplays are efficiently and appropriately used by easily and simplyswitching control patterns according to a power consumption.

In addition, the main CPU 111 causes the first display unit 12 todisplay a time counted by the main CPU 111 in the normal mode, the subCPU 211 causes the first display unit 12 to display a time counted bythe RTC 212 in the low power mode, and the sub CPU 211 causes the seconddisplay unit 22 to display a time counted by the RTC 212 in the pausemode.

In this manner, by gradually reducing process loads related to timecounting and time display, the smart watch 100 can appropriately displaya time corresponding to a power consumption by efficiently andappropriately switching the power consumption.

The present invention is not limited to the above-described embodimentand can be variously changed.

For example, the above embodiment indicates the case where the displayscreen 22 a of the second display unit 22 is stacked on the displayscreen 12 a of the first display unit 12. However, the stack order maybe opposite, or the two display screens may be arranged in parallel. Inaddition, the display screen is not limited to a liquid crystal displayscreen, and an electro-luminescent (EL) display may be used.

Further, the above embodiment indicates that the first display unit 12and the second display unit 22 are arranged one by one. However, aplurality of the first display units 12 (display screens 12 a) and aplurality of the second display units 22 (display screens 22 a) may beprovided.

As a receiving unit, regarding the satellite radio wave receiving module15, it has been described that time information can be acquired byreceiving radio waves from a GPS satellite. However, the timeinformation may be acquired by receiving radio waves from otherpositioning satellites such as GLONASS. Further, in addition toreceiving radio waves, the time information may be obtained by receivinga standard radio waves with long wavelength.

Furthermore, the time information acquired by using the satellite radiowave receiving module 15, may be performed in advance of timeinformation acquisition via the wireless communication controller 14.Alternatively, accurate time information may be obtained by using onlythe satellite radio wave receiving module 15.

In the above embodiment, the satellite radio wave receiving module 15 isconnected to the main microcomputer 11 and acquires time information bycontrol of the main microcomputer 11. However, the satellite radio wavereceiving module 15 may be connected to the sub microcomputer 21, andtime information may be acquired by control of the sub microcomputer 21.

Further, in the above embodiment, a date and a time of the RTC 212 isobtained from the sub CPU 211 after the main microcomputer 11 is startedup, and then the main CPU 111 obtains highly accurate time informationfrom a smart phone and a GPS satellite and corrects times counted by theRTCs 212 and 312. However, highly accurate time information may beobtained first from a smart phone and a GPS satellite immediately afterthe main microcomputer 11 is started up, and then times counted by theRTCs 212 and 312 may be corrected.

In addition, it has been described in the above embodiment that the submicrocomputer 21 and the PMIC 31 each include RTCs 212 and 312. However,a common RTC may be used. In addition, in the sub microcomputer 21, thesub CPU 211 may count a time without using an RTC.

In addition, in the above embodiment, the RTC 312 is included in thePMIC 31. However, the main microcomputer 11 may include the RTC 312.

In addition, the sub CPU 211 corrects a time of the RTCs 212 and 312,but it is not limited to the sub CPU 211. The main CPU 111 may correctthe time. In addition, after the main CPU 111 corrects a time counted bythe main CPU 111, times of the RTCs 212 and 312 may be corrected basedon the corrected time. In addition, such that the sub CPU 211 and themain CPU 111 can independently acquire time information from outside,the wireless communication controller 14 and the satellite radio wavereceiving module 15 may be connected to the sub microcomputer 21 andoperate by control of the sub CPU 211.

Selection of a display unit and display control indicated in theabove-described embodiment and each variation may be determined bycombination corresponding to each power consumption mode as long as bothof them do not conflict to each other. In addition to theabove-described three power consumption modes, an intermediate modeamong the three modes may be included.

In addition, a transition operation of the above-described powerconsumption modes and a display control in response to the transitionare performed in cooperation with the main CPU 111 and the sub CPU 211as a processor. However, these control operations may be partiallyperformed by using a special logical circuit.

In addition, the main CPU 111 may understand a current power consumptionmode of the smart watch 100 in the above power consumption modes, andalso both of the main CPU 111 and the sub CPU 211 may understand themode.

In the above embodiment, a smart watch is exemplified as an electronicdevice in the description. However, the electronic device is notnecessarily a smart watch. The present invention can be preferablyapplied to other display terminals, especially, a portable and wearabletype terminals.

In addition, the configuration indicated in the above-describedembodiment, specific details in a control procedure and a displayexample can be appropriately changed within a scope of the presentinvention.

Embodiments according to the present invention have been describedabove. However, a scope of the present invention is not limited to theabove-described embodiment, and the scope of the present inventiondescribed in Claims and a scope equivalent thereto are included.

The invention claimed is:
 1. An electronic device comprising: a firstprocessor; a second processor; a first display unit; and a seconddisplay unit; wherein: the first processor and the second processorcooperate with each other and perform a display operation including atime display, the first processor can be selectively set to any of anormal mode, a low power mode in which a power consumption is lower thana power consumption in the normal mode, and a pause mode in which apower consumption is lower than the power consumption in the low powermode, and the first processor is stopped, in the normal mode or the lowpower mode, the first processor controls such that the first displayunit displays a time, and the second processor controls such that thesecond display unit does not display a time, in the pause mode, thefirst display unit is turned off, and the second processor controls suchthat the second display unit displays a time, the second processor canbe selectively set to a second normal mode in which the second processornormally operates, and a second low power mode in which the secondprocessor operates with a low power consumption in comparison with thesecond normal mode, wherein the second processor is operable to be setto the second normal mode or the second low power mode separately fromand irrespective of whether the first processor is set to the normalmode, the low power mode, or the pause mode, whereby the secondprocessor can be set to the second normal mode or the second low powermode when the first processor is set to any of the normal mode, thelower power mode, and the pause mode.
 2. The electronic device accordingto claim 1, wherein the second processor operates with at least one of alow power consumption and a low operation frequency in comparison withthe first processor.
 3. The electronic device according to claim 1,wherein the second display unit is stacked on an upper portion of thefirst display unit, and in a state in which the second display unit doesnot display a time, the second display unit is controlled so as totransmit a display content of the first display unit.
 4. A displaycontrol method for an electronic device, the electronic device includinga first processor, a second processor, a first display unit, and asecond display unit, the method comprising: performing a displayoperation including a time display under cooperative control by thefirst processor and the second processor; selectively setting the firstprocessor to any of a normal mode, a low power mode in which a powerconsumption is lower than a power consumption in the normal mode, and apause mode in which a power consumption is lower than a powerconsumption in the low power mode, and the first processor is stopped;in the normal mode or the low power mode, performing control by thefirst processor such that the first display unit displays a time, andperforming control by the second processor such that the second displayunit does not display a time; in the pause mode, performing control suchthat the first display unit is turned off, and performing control by thesecond processor such that the second display unit displays a time;selectively setting the second processor to a second normal mode inwhich the second processor normally operates, and a second low powermode in which the second processor operates with a low power consumptionin comparison with the second normal mode, wherein selectively settingthe second processor to the second normal mode and the second low powermode comprises selectively setting the second processor to the secondnormal mode and the second low power mode separately from andirrespective of whether the first processor is set to the normal mode,the low power mode, or the pause mode, whereby the second processor canbe set to the second normal mode or the second low power mode when thefirst processor is set to any of the normal mode, the lower power mode,and the pause mode.
 5. The display control method according to claim 4,wherein the second processor operates with at least one of a low powerconsumption and a low operation frequency in comparison with the firstprocessor.
 6. The display control method according to claim 4, whereinthe second display unit is stacked on an upper portion of the firstdisplay unit, and in a state in which the second display unit does notdisplay a time, the method comprises controlling the second display unitso as to transmit a display content of the first display unit.